In brief, a fluid lens, sometimes also referred to as an adaptive lens, comprises an interface between two fluids having dissimilar optical indices. The shape of the interface can be changed by the application of external forces so that light passing across the interface can be directed to propagate in desired directions. As a result, the optical characteristics of a fluid lens, such as whether the lens operates as a diverging lens or as a converging lens, and its focal length, can be changed in response to the applied forces.
Fluid lens technology that employs electrical signals to control the operation of the fluid lens has been described variously in Matz, U.S. Pat. No. 2,062,468; Berge et al., U.S. Pat. No. 6,369,954; Onuki et al., U.S. Pat. No. 6,449,081; Tsuboi et al., U.S. Pat. No. 6,702,483; Onuki et al., U.S. Pat. No. 6,806,988; Nagaoka et al., U.S. Patent Application Publication No. 2004/0218283; Takeyama et al., U.S. Patent Application Publication No. 2004/0228003; and Berge, U.S. Patent Application Publication No. 2005/0002113, as well as International Patent Application Publications Nos. WO 99/18546, WO 00/58763, and WO 03/069380.
Additional methods of controlling the operation of fluid lenses include the use of liquid crystal material (Nishioka, U.S. Pat. No. 6,437,925), the application of pressure (Widl, U.S. Pat. No. 6,081,388), the use of elastomeric materials in reconfigurable lenses (Rogers, U.S. Pat. No. 4,514,048), and the uses of micro-electromechanical systems (also known by the acronym “MEMS”) (Gelbart, U.S. Pat. No. 6,747,806).
Further attempts to develop fluid lens control modules may be see in, for example, Sasaya et al., U.S. Pat. No. 6,188,526; de Luca, U.S. Pat. No. 3,161,718; Flint, U.S. Pat. No. 2,300,251; Yao et al., U.S. Patent Application Publication No. 2005/0014306; O'Connor et al., U.S. Patent Application Publication No. 2005/0100270; Massieu, U.S. Patent Application Publication No. 2005/0218231; Michelet, U.S. Pat. No. 4,289,379; Viinikanoja, U.S. Pat. No. 6,936,809; European Patent Application EP 1 674 892 A1; British Patent Specification GB 1327503; Japanese Pat. No. JP2002243918 (Olympus Optical, Application No. JP20010037454); and International Patent Application Publication No. WO 03/071335.
Further examples include Shahinpoor, U.S. Pat. No. 5,389,222; Shahinpoor et al., U.S. Pat. No. 6,109,852; Guy, U.S. Pat. No. 6,542,309; Pelrine et al., U.S. Pat. No. 6,376,971; Ren H., Fox D., Anderson A., Wu B., and Wu S-T, 2006, “Tunable-focus liquid lens controlled using a servo motor”, Optics Express 14(18):8031-8036; Santiago-Alvarado A, Gonzalez-Garcia J, García-Luna J, Fernández-Moreno A, and Vera-Díaz W, 2006, “Analysis and design of an adaptive lens”, Proceedings of SPIE Optics and Photonics 6288:62880S-1-62880S-8; Ghosh T K, Kotek R, and Muth J, 2005, “Development of layered functional fiber based micro-tubes”, National Textile Center Annual Report 1-9; Pelrine R, Kombluh R D, Pei Q, Stanford S, Oh S, Eckerle, J, Full R J, Rosenthal M A, and Meijer K, 2002, “Dielectric elastomer artificial muscle actuators: toward biomimetic motion”, Proc. SPIE 4695:126-137; Chronis N, Liu G L, Jeong K-H, and Lee L P, 2003, “Tunable liquid-filled microlens array integrated with microfluidic network”, Optics Express 11(19):2370-2378; each of which is incorporated herein by reference in its entirety.
However, there is a continuing need for improved systems and methods for using fluid lenses in present day systems.